the best PLC ever

What is the best PLC in the Market?
Why isn't there a common protocol for PLC's.
DNP was designed with bits and pieces of different protocols to get the best performance but why do PLC's have so many different ones

The one your most familiar with is the best!
Why do people have different color hair, why do people have different color eyes, why don't people all look the same?
Your other questions are mute.

The answer to your first question is none. They are all suited to different jobs.

The answer to your second question is also: they are all suited to different jobs.

Both of these topics have been covered here before. Try doing a quick search.

AK

D**n you, Blake!
You line jumped!

sorry for the edit!

One that will never fail no matter what magnitude of surge is fed up the tubes.

One that will program itself and never make a mistake.

One that will anticipate whatever stupid things an operator can do to foul up carefully written and commissioned code.

One that is able to FIX THE MACHINE when it breaks down.

Etc Etc

ishmaelgd what do you mean by different protocol?

Do you mean proramming language?
If so it´s like asking why do you have to have basic,visualbasic, C,C++, java, cobol,pascal and so on..
´

The plc:s have a standard how the programming blocks should look like in eg. ladder. (don´t remember the numeber) almost all of the suppliers make their programs according to that standard.

don´t remember the numeber

Click to expand...

IEC 61131-3

There is no best PLC. We all have our favorites, but a lot of factors go into supplier choice. That includes hardware features, software preference, ease of use vs. ability to perform complex operations, local support, price, and so on.

The reason for the great number of protocols is simply competition between manufacturers. Originally communications was envisioned between PLCs of the same brand on isolated "islands" of automation. It was not common in the early days to have different PLC brands in the same system or at the same facility. MAnufacturers developed communications protocols independently and never intended to allow competitors to cut in on their established base. Proprietary protocols were one way to keep customers "loyal". These same competitive pressures foiled attempts by ISA (Instrument Society of America) and others to develop a universal protocol.

We can only hope that competitive pressure will eventually force manufacturers to cooperate on communications between platforms. The closest thing to that now is Modbus in the US and Profibus in the rest of the world.

The best plc on the market is the one you buy for your personal use, regardless of price.

I had the opportunity to oversee machinery that was using over 20 different brands/models of plcs. These included Allen Bradley, Reliance, GE Fanuc, Sixnet, Cutler Hammer, Horner, Micro's, Shark's, etc.

I had my one favorite, and even though it is out of production, there are still plenty new ones out there. If I could, I would buy them all up.

However, perhaps the best one is one that someone gives you (FREE) including programming software (specially if it "costs").

Whay tyoe will best suit your needs, do you want to pay for extra cost software, will it do th job you want, if is going to a customer will the accept it, can you get support if need be (if so, how much $). Overall, will it do the job and is it cost effective for you?

regards.....casey

The piece best ever????


Hmmmm.. Well... It's hard to say...

There was that green eyed brunette in Flordia, then again that Blonde in Kalamazoo....Nhaaaa. It was the Redhead in Vegas.... OR maybe that Polish one...Sexy accent... Jezzz it's hard to say... Let me sample them all again and I'll let you know...


Ohhhh PLCs... Never mind.

no such a thing as best

ishmaelgd

I do not think there is a best kind of PLC in any market. Different kinds work in different ways, and have different functions. So it really depends on what you need.

Regards
Sher Tang

I'm impressed, no specific brands mention.

I do like larger, or expandable bricks.

regards.....casey

EASY ----- AB Ctrlogix

Is AB Ctrlogix Easy ???